H7Composite plate shear walls—concrete filled (C-PSW/cf)

H7.4a Steel Web Plate of C-PSW/CF with Half-Circular or Circular Boundary Elements

The maximum spacing of tie bars in vertical and horizontal directions, $w_{1}$, shall be as follows:

(H7-1)

where

$E=\operatorname{modulus}$ of elasticity of steel

= 29,000 ksi (200 000 MPa)

$F_{y}=$ specified minimum yield stress, ksi (MPa)

$t$ = thickness of plate, in. (mm)

When tie bars are welded to the steel plates, the thickness of the plate shall develop the tensile strength of the tie bars.

H7.4b Half-Circular or Circular Boundary Elements

The diameter-to-thickness ratio, $D / t$, for the circular part of the C-PSW/CF cross section shall be limited as follows:

(H7-2)

where

$D=$ outside diameter of round hollow structural section (HSS), in. (mm)

$t=$ design wall thickness thickness of HSS, in. (mm)

H7.4c Tie Bars

Tie bars shall be designed to resist the tension force, $T_{r e q}$, while remaining elastic for all applicable load combinations, determined as follows:

(H7-3)

$T_{1}$ is the tension force resulting from the locally buckled web plates developing plastic hinges on horizontal yield lines along the tie bars and at mid-vertical distance between tie-bars and is determined as follows:

(H7-4)

where

$\begin{aligned} t & =\text { thickness of plate, in. (mm) } \\ w_{1}, w_{2} & =\text { vertical and horizontal spacing of tie bars, respectively, in. (mm) }\end{aligned}$

$T_{2}$ is the tension force that develops to prevent splitting of the concrete element on a plane parallel to the steel plate.

(H7-5)

where

$\begin{aligned} F_{y, \text { plate }} & =\text { specified minimum yield stress of plate, ksi (MPa) } \\ t_{s c} & =\text { total thickness of composite plate shear wall, in. (mm) } \\ w_{\min } & =\text { minimum of } w_{1} \text { and } w_{2}, \text { in. (mm) }\end{aligned}$

H7.5a Steel Web and Flange Plates

In regions of flexural yielding (at the base), the steel plate slenderness ratio, $b / t$, shall be limited as follows:

(H7-6)

where

• $E=\operatorname{modulus}$ of elasticity of plate

= 29,000 ksi (200 000 MPa)

• $\begin{aligned} b & =\text { largest unsupported length of plate between rows of steel anchors or ties, in. } \\ & \text { (mm) }\end{aligned}$
• $t=$ thickness of plate, in. (mm)

H7.5b Tie Bars

The maximum spacing of tie bars shall be limited as follows:

(H7-7)

$w_{1} \leq 0.38 t$,

E

$2 \alpha+1$

(H7-7M)

(H7-8)

where

$d_{t i e}=$ diameter of tie bar, in. (mm)

$\begin{aligned} w_{1} & =\text { largest clear spacing of tie bars in vertical and horizontal directions, in. } \\ & \text { (mm) }\end{aligned}$

H7.6a Flexural Strength

The available plastic moment strength of the C-PSW/CF shall be determined in accordance with Specification Section I1.2a.

H7.6b Shear Strength

The available shear strength of C-PSW/CF shall be determined in accordance with Specification Section I4.4.

H7.7a Connection Between Tie Bars and Steel Plates

Connection of the tie bars to the steel plate shall be able to develop the full tension strength of the tie bar.

H7.7b Connection Between C-PSW/CF Steel Components

Welds between the steel web plates and the boundary elements or flange or closure plates shall be compete-joint-penetration groove welds.

H7.7c C-PSW/CF and Foundation Connection

Where the composite walls are connected directly to the foundation at the point of maximum moment in the walls, the composite wall-to-foundation connections shall be detailed such that the connection is able to transfer the base shear force and the axial force acting together with the overturning moment, corresponding to 1.1 times the plastic composite flexural strength of the wall. The plastic composite flexural strength of the wall shall be obtained by the plastic stress distribution method described in Specification Section I1.2a. Applicable $R_{y}$ and $R_{c}$ factors shall be used for different elements of the cross section while establishing section force equilibrium and calculating the flexural strength.

H7.8a Splices

Steel plate and boundary element splices located in the designated protected zones shall develop the full strength of the weaker of the two connected elements.